1. Field of the Invention
The present invention relates to photographic objective lenses and in particular to such lenses that comprise three air spaced elements.
2. Description of the Prior Art
Triplet lenses for use in photographic apparatus are well known and have been used for many years. Moreover, high relative aperture lenses have also been in use for many years in the photographic industry. However, with the advent of available light photography, the use of high relative aperture lenses has spread to photographic apparatus designed to be mass produced for the amateur market. The price of such lenses then becomes of great concern and the relatively complex, well corrected, high relative aperture lenses known in the art are too costly.
Another trend in the photographic industry is toward compact designs to provide convenience in storage, handling and transportation. Large, complex lenses represent a sizable percentage of the camera's volume and place a lower limit on the size of the photographic apparatus. A reduction in the number of elements in a lens will generally aid in reducing the size and cost of the lenses to be incorporated in the photographic apparatus.